Correlated dynamics of three-particle bound states induced by emergent impurities in Bose-Hubbard model

TL;DR

This paper investigates three-particle bound states in the Bose-Hubbard model, revealing how emergent impurities influence their quantum walks, Bloch oscillations, and edge states, providing new insights into their collective dynamics.

Contribution

It uncovers how interaction-induced impurities create distinct bound states and affect their quantum dynamics, advancing understanding of three-particle bound states in lattice systems.

Findings

Dimer-monomer bound state spread velocity is lower than single-particle case.

Bloch oscillation period is one third of the single-particle case.

Bound edge states emerge when defects exceed effective tunneling strength.

Abstract

Bound states, known as particles tied together and moving as a whole, are profound correlated effects induced by particle-particle interactions. While dimer-monomer bound states are manifested as a single particle attached to a dimer bound pair, it is still unclear about quantum walks and Bloch oscillations of dimer-monomer bound states. Here, we revisit three-particle bound states in the Bose-Hubbard model and find that interaction-induced impurities adjacent to bound pair and boundaries cause two kinds of bound states: one is dimer-monomer bound state and the other is bound edge state. In quantum walks, the spread velocity of dimer-monomer bound state is determined by the maximal group velocity of their energy band, which is much smaller than that in the single-particle case. In Bloch oscillations, the period of dimer-monomer bound states is one third of that in the single-particle case. Emergence of bound edge states also requires that interaction-induced defects are greater than the effective tunneling strength of three-particle bound state. Our work provides new insights to basic mechanics and collective dynamics of three-particle bound states.